This transcript has been edited for clarity.
Daniel E. Forman, MD: Hello. My name is Daniel Forman. I am a cardiologist based at the University of Pittsburgh and the VA Pittsburgh Healthcare System. In my clinical and research work, I have strong ties to cardiac rehabilitation and heart failure.
I'm here today with Gordon Reeves, my colleague and friend, to discuss cardiac rehabilitation and the recently published REHAB-HF trial.
Gordon R. Reeves, MD, MPT: Hi. I'm Gordon Reeves. I'm a heart failure cardiologist working at Novant Health in Charlotte, North Carolina. I also have a background as a physical therapist, and like Dan, I have been working in cardiac rehab for heart failure patients and other rehab interventions for heart failure patients as my primary research interests. [Editor's note: Dr Reeves was one of the investigators in the REHAB-HF trial.]
Forman: To introduce this topic, I want to emphasize that cardiac rehabilitation, overall, is a multifaceted program that provides patient education and healthy lifestyle modifications that include both diet and physical activity. It focuses on exercise training and risk factor reduction, stress reduction, and medication adherence. Again, it's multifaceted.
Eligibility for cardiac rehabilitation includes coronary artery disease and revascularization — both coronary artery bypass graft (CABG) and percutaneous coronary intervention (PCI) — and it has expanded over many years to include other types of cardiac conditions, including heart transplant, valvular heart disease, heart failure — particularly heart failure with reduced ejection fraction (HFrEF) — and peripheral arterial disease.
It's also notable to me, and I think to the cardiology community, that in this post–COVID-19 environment, cardiac rehabilitation is in a dynamic phase of development, particularly in regard to new models that are developing that involve telehealth modalities with the notion of remote-based cardiac rehabilitation, hybrid-based rehabilitation, and various types of exercise training regimens.
With that kind of broad context, I want to talk a little bit more about the inclusion of HFrEF into cardiac rehabilitation, and that was relatively recent. It really happened after CMS granted approval in 2014, and it was premised particularly on HF-ACTION, a landmark trial showing the safety and benefits of exercise training for patients with HFrEF. It involved primarily aerobic training for patients who were stable with chronic HFrEF. Exercise training was demonstrated to be safe, which was a big issue. It was a site-based, supervised format for the first 3 months, followed by home-based exercise thereafter.
The benefits were multifold, including reduced cardiovascular disease mortality, improved function, decreased rehospitalization, and many qualitative benefits, such as quality of life. The favorable effects extended to women and the very old.
The REHAB-HF trial, which was published much more recently in The New England Journal of Medicine, showed benefits with a very different type of exercise training regimen, in different types of patients, for acute heart failure.
Gordon will now describe the trial, starting particularly with the study population.
First Look at Patients With Acute HF
Reeves: Thank you, Dan. As you pointed out, HF-ACTION was really the background that helped get us started. As you mentioned, it focused on the chronic, stable outpatient with HFrEF. Establishing safety and efficacy with that lower-risk group was important.
With REHAB-HF, we switched the focus to the acute, decompensated heart failure patient. This population had been excluded from prior cardiac rehab trials because of the safety concerns from recent exacerbation of heart failure and the high rates of events associated with these patients; approximately 50% of these patients are readmitted or experience death within 6 months of hospital discharge.
They also are among the most debilitated population among patients with heart failure. In some of our early studies, we found really broad-based functional impairments, and much more severe than those seen in, for example, the HF-ACTION population, including deficits of balance and mobility, increasing the fall and injury risk, and even just functional strength with simple things like getting up out of a chair. About a quarter of our patients couldn't do that without assistance from someone or using their arms. They lacked the leg strength.
A common metric that most use in cardiac rehab, the 6-minute walk test, was at roughly half that seen in the HF-ACTION population, so this was really a very debilitated group with high rates of frailty. The majority of patients met formal frailty definitions, and almost all of them had at least some features characteristic of frail patients. This was really a very different population with higher risk, but we saw a potentially higher reward as well.
Forman: Gordon, do you want to talk about the actual intervention?
Reeves: Yes. The intervention really grew out of what we identified as these patients' deficits. Because their physical function impairments were so different from prior rehab populations', at least in the heart failure literature, we thought we needed to really modify the intervention to match that.
We enrolled participants in the hospital and got them started on the rehab as soon as they could. We targeted within a week of discharge and actually got them started, on average, within about 10 days. We followed the familiar 3-days-a-week, 3-month structure, but that's really where I think many of the similarities with the more typical cardiac rehab end.
Beyond that, our intervention was quite different. Most notably, patients were not in a group session; they were one-on-one. We included physical therapists because of the balance and mobility deficits. They were part of our rehab team. We made the intervention target all the domains that we had identified, including mobility, balance, and functional strength training, in addition to endurance.
We really tried to focus on balance, mobility, and strength first so that when we moved on to endurance, they would be at less risk for falls and could do that more safely. We also created a very structured progression. These patients are very debilitated and the typical intensity metrics we use in cardiac rehab aren't a good fit. We created a very detailed, structured progression to make sure that they were continuing to make improvements and progress over the course of their rehab in each of the domains. With that, I think we found some pretty exciting results.
Forman: I want to ask you about the results, but before I do, I really want to highlight for the audience that REHAB-HF is not cardiac rehabilitation. You mentioned one-on-one and a very intense training regimen that was really very different from the model of a group-based exercise session in traditional cardiac rehabilitation. It provides important kinds of principles that may be very applicable to a future form of cardiac rehabilitation or care in general for an older population that tends to have cardiac disease, or with frailty and elements of complexity that were not typical, perhaps, of cardiac rehabilitation in the past.
Do you want to talk a little bit about the outcomes, Gordon?
Reeves: Yes, thank you. The study was similar to a phase 2 trial designed to assess improvement in physical function. Our primary physical function endpoint was something called a Short Physical Performance Battery (SPPB), which is very common in the geriatric literature and starting to make gains in the cardiac literature, as you said, with recognition that we're increasingly dealing with older, frail patients. This captures the three domains of gait speed, repeated chair rise (strength test), and a standing balance test score.
With that, we saw significant improvements in physical function. The SPPB is on a 0- to 12-point scale. Our patients improved more than 1.5 points, which is about three times the minimum meaningful change and one of the largest effect sizes that's been reported in the literature to date. In addition to physical function in the SPPB, we also saw improvements in 6-minute walk by over 30 meters and improvements in quality of life, including through the Kansas City Cardiomyopathy Questionnaire (KCCQ), as well as reduction of symptoms of depression.
Encouraging Results for Patients with HFpEF
Forman: Again, I want to reiterate the point I made before. This is not the virtual type of cardiac rehabilitation that you're going to put onto your iPhone and have telehealth models. It's not ready for hybrid and remote. We're not there. If the audience is familiar with contemporary cardiac rehabilitation evolutions, it is not the interventions of REHAB-HF — at least not yet — but the study results still provide some very important principles for the future.
Reeves: Just to echo that, the study intervention was very hands-on. The one-on-one rehab was done partly to make sure participants were constantly progressing, but also for participant safety. We were making sure there were no falls, and closely monitoring how well participants were tolerating the activities. We thought that was one of the keys to the study's success.
We were not powered to assess for clinical events. Therefore, although the results are very encouraging and we're very excited by them, we think they warrant further study. There were fewer than 200 patients participating in the intervention. We think we need to study this again in a larger population of patients and one that's adequately powered for better assessment of safety and efficacy.
I will add that another distinction from many prior rehab trials that had focused on patients with reduced ejection fraction is that we included a heart failure with preserved ejection fraction (HFpEF) population. About half of our study had patients with preserved ejection fraction and the other half had reduced ejection fraction. We subsequently have compared findings for these two groups. They both improved, but if anything, the HFpEF patients seemed to improve more and respond better to this intervention. Going forward, that's really the population we plan to focus on to see if we can improve clinical events.
Forman: For my last comment, I just want to emphasize that this notion of proving efficacy of exercise for HFpEF is kind of the holy grail in the exercise cardiology literature, and I think there are many reasons to think it will be favorable. Certainly, the preliminary data from REHAB-HF suggest a very strong benefit from this approach that is being promulgated by this trial.
Reeves: Agreed. We're very optimistic and look forward to doing that. This is a population of patients who don't have many other therapeutic options. We're particularly excited to see that they responded well to this and hope we're able to study it more.
Forman: Thank you very much.
Reeves: Thank you.
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Cite this: Hands-on for Heart Failure: New Considerations for Cardiac Rehab - Medscape - May 05, 2022.